[PATCH] e1000: Delay clean-up of last Tx packet

Delay clean-up of last Tx packet to fix pre-mature writeback issue of Tx descriptors only when TSO is enabled

Signed-off-by: Mallikarjuna R Chilakala <mallikarjuna.chilakala@intel.com>
Signed-off-by: Ganesh Venkatesan <ganesh.venkatesan@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
diff -up net-drivers-2.6/drivers/net/e1000/e1000_main.c net-drivers-2.6/drivers/net/e1000.new/e1000_main.c

1 files changed, 27 insertions, 16 deletions

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 9c6c1fbbc412..4a8c069e6c7c 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -2384,11 +2384,10 @@ e1000_clean_tx_irq(struct e1000_adapter *adapter)
         eop_desc = E1000_TX_DESC(*tx_ring, eop);
 
         while(eop_desc->upper.data & cpu_to_le32(E1000_TXD_STAT_DD)) {
-                /* pre-mature writeback of Tx descriptors     */
-                /* clear (free buffers and unmap pci_mapping) */
-                /* previous_buffer_info                       */
+                /* Premature writeback of Tx descriptors clear (free buffers
+                 * and unmap pci_mapping) previous_buffer_info */
                 if (likely(adapter->previous_buffer_info.skb != NULL)) {
-                        e1000_unmap_and_free_tx_resource(adapter, 
+                        e1000_unmap_and_free_tx_resource(adapter,
                                         &adapter->previous_buffer_info);
                 }
 
@@ -2397,20 +2396,25 @@ e1000_clean_tx_irq(struct e1000_adapter *adapter)
                         buffer_info = &tx_ring->buffer_info[i];
                         cleaned = (i == eop);
 
-                        /* pre-mature writeback of Tx descriptors */
-                        /* save the cleaning of the this for the  */
-                        /* next iteration                         */
-                        if (cleaned) {
-                                memcpy(&adapter->previous_buffer_info,
-                                        buffer_info,
-                                        sizeof(struct e1000_buffer));
-                                memset(buffer_info,
-                                        0,
-                                        sizeof(struct e1000_buffer));
+#ifdef NETIF_F_TSO
+                        if (!(netdev->features & NETIF_F_TSO)) {
+#endif
+                                e1000_unmap_and_free_tx_resource(adapter,
+                                                                 buffer_info);
+#ifdef NETIF_F_TSO
                         } else {
-                                e1000_unmap_and_free_tx_resource(adapter, 
-                                                        buffer_info);
+                                if (cleaned) {
+                                        memcpy(&adapter->previous_buffer_info,
+                                               buffer_info,
+                                               sizeof(struct e1000_buffer));
+                                        memset(buffer_info, 0,
+                                               sizeof(struct e1000_buffer));
+                                } else {
+                                        e1000_unmap_and_free_tx_resource(
+                                            adapter, buffer_info);
+                                }
                         }
+#endif
 
                         tx_desc->buffer_addr = 0;
                         tx_desc->lower.data = 0;
@@ -2443,7 +2447,14 @@ e1000_clean_tx_irq(struct e1000_adapter *adapter)
                    !(E1000_READ_REG(&adapter->hw, STATUS) & E1000_STATUS_TXOFF))
                         netif_stop_queue(netdev);
         }
+#ifdef NETIF_F_TSO
 
+        if( unlikely(!(eop_desc->upper.data & cpu_to_le32(E1000_TXD_STAT_DD)) &&
+            time_after(jiffies, adapter->previous_buffer_info.time_stamp + HZ)))
+                e1000_unmap_and_free_tx_resource(
+                    adapter, &adapter->previous_buffer_info);
+
+#endif
         return cleaned;
 }